Chop leaves and stems of tarragon and chervil coarsely and combine with the shallots, peppercorns, vinegar, and white wine in a small sauce pan. Cook over high heat until liquid is reduced to two thirds original volume. Strain and place juices on top of a double boiler. Beat egg yolks with water and add to juices on top of double boiler. Simmer over hot but not boiling water, stir briskly with a whisk until light and fluffy. Never let the water boil as the sauce will not take. Add the butter gradually to the sauce, stirring as the sauce thickens. Continue until sauce is thick. Season to taste with salt, cayenne pepper, and lemon juice. Strain through a fine sieve and serve. Excellent with fish.{$7e}(Original recipe for 4)